1. Field of the Invention
The present invention relates generally to an aerosol dispensing inhaler training device, and in particular, to an aerosol dispensing inhaler training device that can monitor several parameters, such as the flow rate, shaking of the container and the activation of the container comprising a solution or suspension which upon actuation transforms into an aerosol.
2. Description of Related Art
Aerosol administered medication for bronchial therapy in such conditions as asthma, chronic bronchitis and emphysema is generally the preferred dosage technique for reasons of efficacy, reduced side effects and economy. Such particulate drugs are commonly prescribed using metered dose inhaler (MDI) type devices. It is well recognized that improper inhalation technique in the use of MDI devices is a serious barrier to effective therapy.
Some patients may have difficulty in the use of conventional MDI devices especially in terms of controlling inhalation, and proper activation timing of the MDI delivery system. For example, patients may inhale too fast, or in an erratic manner. Another common problem is that patients may delay activation of the MDI device until after inspiration has started, and therefore, the crucial initial portion of the inspired breath does not contain medication. After activation, patients may frequently begin their MDI inspiration breaths at improper levels of lung volume, for example, their lungs may already be relatively full of air and therefore a proper large volume of inspired air is impossible.
Once the proper MDI inspiration breath has been achieved, it is important for the patient to sustain a brief period of breath holding so that the medicated mist is properly deposited in the airways of the patient.
The desired time interval of breath holding is generally thought to be about five to ten seconds. However, this desirable time may be functionally limited, as dictated by individual patient needs and breath holding capabilities.
While it is generally felt the timing of MDI activation should be simultaneous with the beginning of inspiration, there is some scientific opinion that questions whether said activation should be a fraction of a second before or after the beginning of inspiration. However, it is understood that these events are substantially concurrent.
It should be apparent from the above, that while the act of using an MDI device may appear simple, it can be in fact a complex act, and the proper performance of this technique is crucial to the optimal delivery of drugs to the bronchial airways. Without proper MDI inhalation technique, the patient may in fact derive little or no benefit from this form of drug therapy.
In this vein, there have been attempts in the past to measure the magnitude of the flow rate and the timing of the dispensing of the aerosol along with improving the training of individuals to use a proper MDI inhalation technique. In the case of measuring the flow rate, many techniques have been used in the past ranging from pressure differential techniques (i.e., pneumotachs that measure pressure drop across a time meshed screen with a linear resistance, a bundle of capillary tubes with a linear resistance, a fixed orifice or a flexible orifice) to mechanical techniques (i.e., spinning turbines, paddle wheels, hinged flaps with potentiometers) to ultrasonic techniques (i.e., time of flight pulses). One disadvantage to the above flow rate techniques, except the ultrasonics technique, is that the liquid particles present in a patient""s exhaled gas can contaminate the flow rate devices to the extent that they produce inaccurate readings. The ultrasonics technique suffers the drawback that it requires relatively expensive piezoelectric elements and complex signal analysis that limits widespread application.
In the case of teaching proper usage of a metered dose inhaler, past devices and systems have omitted teaching the proper technique for shaking the aerosol container prior to inhalation.
One aspect of the present invention regards an aerosol dispensing inhaler training device for determining whether a user is properly operating an aerosol dispensing device. The training device includes an aerosol dispensing device having a container with a valve stem extending longitudinally therefrom and movable between a closed position and an open position. The container dispenses a portion of the contents within the container when the valve stem is moved to the open position. The aerosol dispensing device includes a housing adapted to support the container reciprocally moveable within the housing along a longitudinal axis from a first position, the housing comprising a well adapted to receive the valve stem and an exhaust port comprising one end in fluid communication with the well and a second end in fluid communication with the ambient atmosphere, wherein said portion of the contents within the container is dispensed from the first end of the exhaust port to the second end of the exhaust port when the housing moves to an actuation position where the valve stem is actuated so that a portion of the contents within the container is dispensed through the second end of the exhaust port when the valve stem is moved to the open position. An actuation sensor generates a signal that indicates when the container is moved to the actuation position and the valve stem is actuated. A shake sensor determines whether the contents within the container have been properly shaken for consumption by a user.
A second aspect of the present invention regards a method of training an individual on how to properly use an aerosol dispensing device. The method includes providing an aerosol dispensing inhaler training device with a container, agitating the contents of the container, determining whether the contents of the container have been properly agitated during the agitating step for consumption by an individual; and repeating the previous steps if it is determined that during the agitating step that the contents of the container have not been properly agitated for consumption by an individual.
The present invention provides significant advantages over other aerosol dispensing inhaler training devices. In particular, several aspects of the present invention""s use of a flow rate measurement device with reduced risk of being contaminated by a patient""s exhaled gas while at the same time having a simple and economical structure.
Another advantage of several aspects of the present invention is that it regards a device and method for teaching the proper technique for shaking a container prior to inhalation.
The present invention, together with further objects and advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.